U.S. scientists said the use of computer-generated facial composites during criminal investigations don't produce useful images of perpetrators.

Gary Wells and Lisa Hasels of Iowa State University pointed to several studies in which individuals attempted to create composites of celebrities.

In one study, 2.8 percent of participants correctly named a well-known celebrity's image that had been created by other participants using the face-composite software. In another study, participants were unable to discriminate composites of classmates from composites of students at different schools.

The researchers say the poor results represent a mismatch between how faces are remembered and how composites are produced.

"Numerous lines of evidence converge on the view that faces are generally processed, stored and retrieved at a holistic level rather than at the level of individual facial features," they said.

Wells and Hasels detailed their study in the February issue of the journal Current Directions in Psychological Science.

Copyright 2007 by United Press International